Electron tube



y W o. BAIER :r m. 2,201,216

ELECTRON TUBE I Filed Jan. 25, 193'! 2 orzzey Patented May 21, 1940 "2,201,216"

"ELECTRON TUBE Otto Baler, Berlln-Reinickendorf, and Curt Jung- Zaeper, Berlin-Wilmersdort, Germany, assignors to C. Lorenz Aktiengesellschatt, Berlin- Tempelhoi', Lorenzweg, Germany, a company Application January 25, 1937, Serial No. 122,216

' In Germany January 24, 1936 11 Claims. (01. 250-215) (Granted under the" provisions of sec. 14, act of March 2, 1927; 357 0. G.

In order to produce very high frequencies the I so asto form a coating thereon. Methodsofthi so called Habann tube has come into use. Such a. kind are well known. In order to effect them, siltube has asplit anode cylinder located in a mag- Ver is molten ontothe ceramic material so as to netic field. Connected to the parts or divisions produce a coating thereon, and this silver coat- 5 of this anode is an oscillatory circuit or Lecher ing is increased in thickness by electro-plating or wire system. The wavelength is in part dependent upon the tuning given to this oscillatory circuit or Lecher wire system. In the case of'very high frequencies the oscillatory circuit or Lecher wire system has been arranged within the vacuum vessel. This arrangement, however, as compared with those wherein the oscillatory circuit or Lecher wire system is closed outside the vacuum vessel, has the disadvantage that variations of the tuning can not be effected, or at least are extremely difficult to effect after the tube has been finished. Therefore tubes are wanted whose vacuum vessel is not much larger in its outer diamter than the anode.

In accordance with the invention tubes ,-of this kind are made with the aid of ceramic materials. Preferably, the anode divisions are burnt or molten onto such ceramic material in a well known manner. The advantages peculiar to arrangements as provided by the invention will be understood from the following description in which some embodiments of the invention are disclosed by way of example, reference being had to the accompanying drawing in which :2) Fig. 1 shows a longitudinal section of a split anode tube or so called Habann-tube as provided by the invention. Fig. 2 represents a section on line 2-2 of Fig. 1. Fig. 3 is a cross-sectional view representing a second form of Habann tube.

,--,,', Fig. 4 is a cross-sectional view of a third form of Habann tube. Fig. 5 is a fragmentary cross-sectional view representing a slight modification of the arrangement shown in Fig. 4. Fig. 6 is a view similar to Fig. 5 and illustrates a modification of the arrangement disclosed in Fig. 4. Fig. '7 is an end view illustrating an example of a split anode.

Fig. 8 shows a section on line 8-8 of Fig. 'I.

The vacuum vessel illustrated in Figs. 1 and 2 consists of a tubular wall I made of a ceramic material. Wall I is at its two ends united with covers 2, 3 fastened thereto by molten glass I1, for instance. Instead of glass any other suitable means may be arranged to provide for vacuumtightness. Within the vessel I, 2, 3 electrodes 4, ,1 5 are disposed which constitute the anode cylinder of the Habann tube. The electrodes 4, 5 may be for instance pieces of sheet copper placed onto wall I so as to be supported thereby. It is however'particularly advantageous to employ a method by which such electrodes are produced on wall the advantage that the construction thus obtained is particularly stable and'hence capable of resisting shocks. The electrodes 4, 5 are provided with leads 6, 1 inserted in the wall I in a manner to ensure the requisite vacuumtightness. Wall I is fitted with a tubular extension 8 where a pump is connected in order to evacuate the vessel in a well known manner. Extension 8 may be of glass, for instance, united with the ceramicwall' I by melting, and is sealed off after evacuation, as is well known with devices of this kind. The cathode 9 is supported, by the covers 2, 3 and may consist of a helix of tungsten wire sealed into the covers 2, 3. The outer circuit is suitably joined to the ends of the heating filament. Also, a bar-shaped cathode may be used that consists of a ceramic bar provided with a metal coating.

In addition to the advantages before described the arrangement represented in Figs. 1 and 2 has the advantage of being very compact, whereby the magnet poles which in a well known manner are associatedwith a Habann tube may be arranged in close proximity thereto. Furthermore, in the manufacture of such tubes the walls I may 'be obtained simply by cutting a ceramic tube in pieces of the length of such walls, whereby the manufacture will be cheaper than has been the case heretofore.

As shown in Fig. 3, Lecher wire systems formed of metal coatings I2, I3 may be connected to the anode parts 4, 5. This construction has proved to be suitable for the production of very steady oscillations. The high frequency energy is taken from the Lecher wire systems by galvanic contact or capacitively or inductively. This, however, is no feature of the invention and therefore is not illustrated.

While the anode shown in Figs. 1, 2, 3 is made in two parts yet it is to be understood that the invention is in the same manner applicable also with Habann tubes whose anodes are made in more than two parts. An example of this is shown in Fig. 4.

The Habann tube shown in Fig. 4 is atube whose anode cylinder is made in four parts I4. This tube has a bar shaped cathode 9A consisting of a ceramic bar 93 having a metal coating 90. In the vacuum vessel l ceramic sockets I 5 are inserted whose internal ends carry the anode diby a die-casting method. This arrangement has of the wall I.

visions M. The sockets it are sealed into the vessel 1, as indicated at IT, so as to ensure vacuumtightness. The arrangement of sockets l5 closed by the anodedivlsions N has the advantage that an intense cooling of the anode divisions is enabled, being effected either by air or by a, liquid such as water. To such end a conduit 25 may be disposed within each socket l5 in the manner shown in Fig. 4,-so as to cause the cooling medium to flow in the directionof the arrows.

This mode of cooling is known from the X-ray tubes and presents the advantage that with the aid of simple means a very intense cooling of the small electrodes is obtained.

In theconstruction according to Figs. 4 and 5 the electrodes M have a tubular extension it which embraces the respective ceramic socket i5. Appropriately, extension l6 and the anode division it are manufactured in a lathe in one piece of copper, for instance. l6 are preferably fitted to the sockets 55 by being shrunk thereon. These extensions are long enough to slightly project beyond the perimeter At ll the ceramic socket I5, metal extension l6 and vessel l are united with each other by melting; This may be eifected for instance by means of a short glass tube or ring, which is inserted over socket l5 and extension l6, and then caused in an oven to melt. In order to usehere a simple piece of glass tube obtained by cutting a glass tube in pieces, vessel l is turned down at I! so as to be provided here with a plane face 26. If no such face were provided then the melting process would not be easy to effect, because in such case the vessel l and the piece of glass tube would be in the geometrical relation of two cylinders one of which is penetrating the other, the penetration figure not being plane. The cathode 9 may be a bar-shaped ceramic body and fitted with a metal coating as above described.

The arrangement shown in Fig. 6 is such that the current is easier to supply to the electrodes than in the case of Figs. 4 and 5. Extension I6 is here shorter'than in Figs. 4 and 5. Socket I5 is provided with a thin metal coating l8 that may be produced thereon by melting, for instance, and to which a current lead 21 is connected. It will be seen that a sort of so called metal skin bushing is employed here. Extension l6 and parts l5, l8 are held together by glass sealings l1, l9 which provide for vacuumtightness. 1

The anode divisions may be associated with each other in the manner shown in Figs. 7 and 8. Anode divisions 2| and 23 are interconnected by bows A and B, each of these being located in a recess 0 of the anode divisions 22', 24, respectively.

The described embodiments of the are of a very solid construction and completely The extensions invention fulfil the requirements before referred to, such as the requirement that the outer diameter oi A the vessel should be small enough.

What is claimed is:

1. An electron tube comprising a ceramic vacuum vessel, a split anode anda cathode within said vessel, and hollow ceramic studs sealed in the walls of said vessel and projecting inwardly from the wall thereof, the parts of said anode being fixed to theinner ends of said studs.

2. An electron tube according to claim 1, wherein the anode divisions have an extension shrunk onto-said ceramic support each anode division closing off the inner end of the associated ceramic support.

3. An electron tube according to claim 1, wherein the ceramic supports have a metal sheath connected to the anode division carried by them and extending out of the ceramic vessel.

4. An electron tube according to claim 1,

wherein the ceramic vessel is composed of a surrounding the support and being normal thereto.

6. An electron tube according to claim 1, wherein the ceramic parts are fastened to each other by a. glass seal.

,7. An electron tube according to claim 1, I

wherein each of the anode divisions has an extension embracing the support carrying this extension, the external and of this extension reaching into a glass seal by which the said vessel and socket are held together.

8; An electron tube according to claim 1, having a bar-shaped cathode.

,9. An electron tube according to claim 1, having a bar-shaped cathode made of a ceramic body fitted with a metal coating.

10. An electron tube comprising a ceramic vacuum vessel, an anode and a cathode within said vessel and a hollow ceramic support projecting inwardly from the wall of said vessel and supporting said anode, said ceramic support also extending outwardly from the wall of said vessel.

11. An electron tube comprising a ceramic vacuum vessel, an anode and a cathode in said i the wall of said vessel.

o'r'ro BAIER. CURT JUNG-ZAEPER. 

